Final answer:
The Missouri Compromise addressed sectional tensions by admitting Missouri as a slave state and Maine as a free state, keeping a numerical balance in Congress. The 36°30' line was established to limit the spread of slavery in new territories in the Louisiana Purchase, offering a temporary yet fragile truce to the slavery conflict in the United States.
Step-by-step explanation:
The Missouri Compromise had a significant impact on the sectional tensions in the United States, particularly in the context of the slavery debate. The compromise, lead by Henry Clay, allowed Missouri and Maine to enter the Union at the same time, with Missouri as a slave state and Maine as a free state. This maintained the balance between slave and free states in Congress and delayed further conflict over slavery.
The establishment of the 36°30' line as part of the Missouri Compromise was a pivotal aspect of the agreement. This line, which delineated the boundary between slave and free territories in the lands acquired from the Louisiana Purchase, prohibited slavery north of the line, with Missouri being the key exception. Although it temporarily resolved sectional conflicts, it also set a precedent for future territorial expansions and the continuing controversy over slavery's reach. The debates and rivalries over these issues would simmer until the Civil War.